1. Field of the Invention
This invention relates to a strand carrier for a strand fabricating machine, such as in a winding or braiding machine and more specifically, to such a carrier which controls the rotation of the bobbin to ensure controlled unwinding of the strand therefrom.
2. Description of the Prior Art
There have heretofore been used a number of braiding machines in the strand fabricating art such as those disclosed in U.S. Pat. Nos. 1,059,523, 1,491,839 and 1,888,477 and, more recently, in U.S. Pat. No. 3,756,117. Throughout the use of such machines there has been a continuing concern for controlled unwinding of the strand from the various bobbins used thereon. It is important to maintain the strands in a taunt condition throughout braiding to prevent ballooning as the strands are rapidly and repeatedly directed inwardly and outwardly of each other. As braiding machine speeds increase, control of the strands becomes even more critical.
Accordingly, there have existed a number of strand carrier devices in the past designed for controlled unwinding of strands from the bobbins. One type has been particularly popular includes a ratchet feature which controllably restricts and releases the bobbin for rotation to supply the strand according to the demand thereon. This type of carrier is generally disclosed in U.S. Pat. Nos. 3,004,463, 3,045,526, 3,038,367, 3,324,757, 3,362,282 and 3,425,315. There also exists a number of strand carriers which employ a variable braking approach by the application of frictional force through a disc or shoe type device to restrict rotation of a bobbin according to the demand for strand therefrom. Various strand carriers utilizing this type of configuration are demonstrated in U.S. Pat. Nos. 2,024,104, 2,988,300, 3,756,533 and 3,002,643.
However, in both general types of control utilized in the embodiment described hereinabove, there have existed problems which have affected their attractiveness for use in braiding machines. The first type is quite noisy and the repeated stopping and starting of the bobbin has not always provided the desired smooth operation which rapid braiding machines require. The second type, although operating much quieter and smoother, employed braking systems which were difficult to control and adjust.
Consequently, it is not surprising that a new method of controlling the rotation of a bobbin has been employed which eliminates the disadvantages of the devices described hereinabove. This new method employs a helical clutch spring which closely encircles a hub portion of the bobbin carrier for controlled application of friction thereto. Configurations which generally employ a clutch spring can be seen in U.S. Pat. Nos. 3,727,732, 3,817,147, 3,839,939 and 3,882,757. However, even strand carriers which have heretofore utilized this method have been found to be extremely complicated or to lack simple but adequate means for proper adjustment when used on winding or braiding machines.